From 499b7fcfa9f3e8535a4500143a9d7af7b67c6984 Mon Sep 17 00:00:00 2001 From: Paul Davis Date: Mon, 5 Aug 2013 13:55:50 -0400 Subject: document PortEngine API --- libs/ardour/ardour/port_engine.h | 215 ++++++++++++++++++++++++++++++++++----- 1 file changed, 190 insertions(+), 25 deletions(-) (limited to 'libs/ardour/ardour/port_engine.h') diff --git a/libs/ardour/ardour/port_engine.h b/libs/ardour/ardour/port_engine.h index f03a8e263f..8e36ad8b09 100644 --- a/libs/ardour/ardour/port_engine.h +++ b/libs/ardour/ardour/port_engine.h @@ -89,73 +89,237 @@ class PortEngine { typedef void* PortHandle; + /** Return a typeless pointer to an object that may be of interest + * that understands the internals of a particular PortEngine + * implementation. + * + * XXX the existence of this method is a band-aid over some design + * issues and will it will be removed in the future + */ virtual void* private_handle() const = 0; + /** Return the name of this process as used by the port manager + * when naming ports. + */ virtual const std::string& my_name() const = 0; + /** Return the maximum size of a port name + */ virtual uint32_t port_name_size() const = 0; - virtual int set_port_name (PortHandle, const std::string&) = 0; + /** Returns zero if the port referred to by @param port was set to @param + * name. Return non-zero otherwise. + */ + virtual int set_port_name (PortHandle port, const std::string& name) = 0; + /** Return the name of the port referred to by @param port. If the port + * does not exist, return an empty string. + */ virtual std::string get_port_name (PortHandle) const = 0; + /** Return a reference to a port with the fullname @param name. Return + * a null pointer if no such port exists. + */ virtual PortHandle* get_port_by_name (const std::string&) const = 0; - /* Discovering the set of ports whose names, types and flags match - * specified values. + /** Find the set of ports whose names, types and flags match + * specified values, place the names of each port into @param ports, + * and return the count of the number found. + * + * To avoid selecting by name, pass an empty string for @param + * port_name_pattern. + * + * To avoid selecting by type, pass DataType::NIL as @param type. + * + * To avoid selecting by flags, pass PortFlags (0) as @param flags. */ + virtual int get_ports (const std::string& port_name_pattern, DataType type, PortFlags flags, std::vector& ports) const = 0; - virtual int get_ports (const std::string& port_name_pattern, DataType type, PortFlags flags, std::vector&) const = 0; + /** Return the Ardour data type handled by the port referred to by @param + * port. Returns DataType::NIL if the port does not exist. + */ + virtual DataType port_data_type (PortHandle port) const = 0; - virtual DataType port_data_type (PortHandle) const = 0; + /** Create a new port whose fullname will be the conjuction of my_name(), + * ":" and @param shortname. The port will handle data specified by @param + * type and will have the flags given by @param flags. If successfull, + * return a reference to the port, otherwise return a null pointer. + */ + virtual PortHandle register_port (const std::string& shortname, ARDOUR::DataType type, ARDOUR::PortFlags flags) = 0; - virtual PortHandle register_port (const std::string& shortname, ARDOUR::DataType, ARDOUR::PortFlags) = 0; + /* Destroy the port referred to by @param port, including all resources + * associated with it. This will also disconnect @param port from any ports it + * is connected to. + */ virtual void unregister_port (PortHandle) = 0; /* Connection management */ + /** Ensure that data written to the port named by @param src will be + * readable from the port named by @param dst. Return zero on success, + * non-zero otherwise. + */ virtual int connect (const std::string& src, const std::string& dst) = 0; + + /** Remove any existing connection between the ports named by @param src and + * @param dst. Return zero on success, non-zero otherwise. + */ virtual int disconnect (const std::string& src, const std::string& dst) = 0; - virtual int connect (PortHandle, const std::string&) = 0; - virtual int disconnect (PortHandle, const std::string&) = 0; - virtual int disconnect_all (PortHandle) = 0; + + /** Ensure that data written to the port referenced by @param portwill be + * readable from the port named by @param dst. Return zero on success, + * non-zero otherwise. + */ + virtual int connect (PortHandle src, const std::string& dst) = 0; + /** Remove any existing connection between the port referenced by @param src and + * the port named @param dst. Return zero on success, non-zero otherwise. + */ + virtual int disconnect (PortHandle src, const std::string& dst) = 0; + + /** Remove all connections between the port referred to by @param port and + * any other ports. Return zero on success, non-zero otherwise. + */ + virtual int disconnect_all (PortHandle port) = 0; - virtual bool connected (PortHandle) = 0; - virtual bool connected_to (PortHandle, const std::string&) = 0; - virtual bool physically_connected (PortHandle) = 0; - virtual int get_connections (PortHandle, std::vector&) = 0; + /** Return true if the port referred to by @param port has any connections + * to other ports. Return false otherwise. + */ + virtual bool connected (PortHandle port) = 0; + /** Return true if the port referred to by @param port is connected to + * the port named by @param name. Return false otherwise. + */ + virtual bool connected_to (PortHandle, const std::string& name) = 0; + + /** Return true if the port referred to by @param port has any connections + * to ports marked with the PortFlag IsPhysical. Return false otherwise. + */ + virtual bool physically_connected (PortHandle port) = 0; + + /** Place the names of all ports connected to the port named by @param + * ports into @param names, and return the number of connections. + */ + virtual int get_connections (PortHandle port, std::vector& names) = 0; /* MIDI */ + /** Retrieve a MIDI event from the data at @param port_buffer. The event + number to be retrieved is given by @param event_index (a value of zero + indicates that the first event in the port_buffer should be retrieved). + * + * The data associated with the event will be copied into the buffer at + * @param buf and the number of bytes written will be stored in @param + * size. The timestamp of the event (which is always relative to the start + * of the current process cycle, in samples) will be stored in @param + * timestamp + */ virtual int midi_event_get (pframes_t& timestamp, size_t& size, uint8_t** buf, void* port_buffer, uint32_t event_index) = 0; + + /** Place a MIDI event consisting of @param size bytes copied from the data + * at @param buf into the port buffer referred to by @param + * port_buffer. The MIDI event will be marked with a time given by @param + * timestamp. Return zero on success, non-zero otherwise. + * + * Events must be added monotonically to a port buffer. An attempt to + * add a non-monotonic event (e.g. out-of-order) will cause this method + * to return a failure status. + */ virtual int midi_event_put (void* port_buffer, pframes_t timestamp, const uint8_t* buffer, size_t size) = 0; + + /** Return the number of MIDI events in the data at @param port_buffer + */ virtual uint32_t get_midi_event_count (void* port_buffer) = 0; + + /** Clear the buffer at @param port_buffer of all MIDI events. + * + * After a call to this method, an immediate, subsequent call to + * get_midi_event_count() with the same @param port_buffer argument must + * return zero. + */ virtual void midi_clear (void* port_buffer) = 0; /* Monitoring */ + /** Return true if the implementation can offer input monitoring. + * + * Input monitoring involves the (selective) routing of incoming data + * to an outgoing data stream, without the data being passed to the CPU. + * + * Only certain audio hardware can provide this, and only certain audio + * APIs can offer it. + */ virtual bool can_monitor_input() const = 0; - virtual int request_input_monitoring (PortHandle, bool) = 0; - virtual int ensure_input_monitoring (PortHandle, bool) = 0; - virtual bool monitoring_input (PortHandle) = 0; + /** Increment or decrement the number of requests to monitor the input + * of the hardware channel represented by the port referred to by @param + * port. + * + * If the number of requests rises above zero, input monitoring will + * be enabled (if can_monitor_input() returns true for the implementation). + * + * If the number of requests falls to zero, input monitoring will be + * disabled (if can_monitor_input() returns true for the implementation) + */ + virtual int request_input_monitoring (PortHandle port, bool yn) = 0; + /* Force input monitoring of the hardware channel represented by the port + * referred to by @param port to be on or off, depending on the true/false + * status of @param yn. The request count is ignored when using this + * method, so if this is called with yn set to false, input monitoring will + * be disabled regardless of the number of requests to enable it. + */ + virtual int ensure_input_monitoring (PortHandle port, bool yn) = 0; + /** Return true if input monitoring is enabled for the hardware channel + * represented by the port referred to by @param port. Return false + * otherwise. + */ + virtual bool monitoring_input (PortHandle port) = 0; /* Latency management */ - virtual void set_latency_range (PortHandle, bool for_playback, LatencyRange) = 0; - virtual LatencyRange get_latency_range (PortHandle, bool for_playback) = 0; + /** Set the latency range for the port referred to by @param port to @param + * r. The playback range will be set if @param for_playback is true, + * otherwise the capture range will be set. + */ + virtual void set_latency_range (PortHandle port, bool for_playback, LatencyRange r) = 0; + /** Return the latency range for the port referred to by @param port. + * The playback range will be returned if @param for_playback is true, + * otherwise the capture range will be returned. + */ + virtual LatencyRange get_latency_range (PortHandle port, bool for_playback) = 0; /* Discovering physical ports */ - virtual bool port_is_physical (PortHandle) const = 0; - virtual void get_physical_outputs (DataType type, std::vector&) = 0; - virtual void get_physical_inputs (DataType type, std::vector&) = 0; + /** Return true if the port referred to by @param port has the IsPhysical + * flag set. Return false otherwise. + */ + virtual bool port_is_physical (PortHandle port) const = 0; + + /** Store into @param names the names of all ports with the IsOutput and + * IsPhysical flag set, that handle data of type @param type. + * + * This can be used to discover outputs associated with hardware devices. + */ + virtual void get_physical_outputs (DataType type, std::vector& names) = 0; + /** Store into @param names the names of all ports with the IsInput and + * IsPhysical flags set, that handle data of type @param type. + * + * This can be used to discover inputs associated with hardware devices. + */ + virtual void get_physical_inputs (DataType type, std::vector& names) = 0; + /** Return the total count (possibly mixed between different data types) + of the number of ports with the IsPhysical and IsOutput flags set. + */ virtual ChanCount n_physical_outputs () const = 0; + /** Return the total count (possibly mixed between different data types) + of the number of ports with the IsPhysical and IsInput flags set. + */ virtual ChanCount n_physical_inputs () const = 0; - /* getting the port buffer. untyped (void*) because this will return - * buffers containing different data depending on the port type + /** Return the address of the memory area where data for the port can be + * written (if the port has the PortFlag IsOutput set) or read (if the port + * has the PortFlag IsInput set). + * + * The return value is untyped because buffers containing different data + * depending on the port type. */ - virtual void* get_buffer (PortHandle, pframes_t) = 0; /* MIDI ports (the ones in libmidi++) need this to be able to correctly @@ -165,7 +329,8 @@ class PortEngine { * * Return the time according to the sample clock in use when the current * buffer process cycle began. - * + * + * XXX to be removed after some more design cleanup. */ virtual pframes_t sample_time_at_cycle_start () = 0; -- cgit v1.2.3